Designated Market Area (DMA)
The term, Designated Market Area (DMA) is used by Nielsen Media Research, and they control the trademark on it. DMAs are used by Nielsen Media Research to identify TV stations that best reach an area and attract the most viewers. There are 210 Nielsen DMAs in the United States, 56 of which are metered (in other words, viewership in these markets are estimated automatically instead of through the archaic diary system still in use in the smaller markets).
Last Update: October 4, 2013